Isothermal-isobaric molecular dynamics simulations were carried out for SnI4 in its liquid state under hydrostatic pressure up to about 5 GPa. The equation of state was obtained from the virial pressure. which was found to be in good agreement with that derived by Boublik regarding a system consisting of hard-convex bodies as a reference fluid. The virial coefficients determined from the equation of state were presented so as to facilitate experimental confirmation.